Engine starter



ENGINE STARTER Filed Nov. 15; 1950 IIIIIIII/I l/VVENTOR William L.McGrath- 11y Maurice P Whiine M J. /z TTOIRNEV Patented Oct. 18, 1932UNITED STATES PATENT OFFICE WILLIAM L. MCGRATH AND MAURICE P. WHITNEY,OF ELMIRA, NEW YORK, ASSIGNOBS 'I'O ECLIPSE MACHINE COMPANY, OF ELMIRA,NEW YORK, A CORPORATION OF NEW YORK ENGINE STARTER Application filedNovember 15, 1980. Serial No. 495,901.

This invention relates to engine starters and more particularly to adrive or transmission adapted to automatically connect and disconnect astarting motor from an element, such as the flywheel, of an internalcombustion engine to be started.

The invention as herein disclosed is embodied in a drive of thescrew-shift type in which a pinion is adapted to be driven by astartingmotor, the pinion being automatically traversed into mesh with aflywheel gear by acceleration of the starting motor, and out of meshtherewith when the engine starts.

One object of the present invention is to provide a novel automaticshift which is efficient and powerful but of small overall dimensions.

Another object of the invention is to provide such a drive including anovel and efficient arrangement of yielding elements for insuringmeshing and the transmission of cranking torque.

Another object is to provide such a drive including new and improvedanti-drift means and positioning means for yieldably maintaining thepinion and the pinion actuating member in their normal positionsrelative to the engine member.

Further objects and advantages will become apparent to those skilled inthis art from the following description taken in connection with theaccompanying drawing in which;

Fig. 1 isa side elevation, partly in section, of a preferred form of thepresent in- I vention;

Fig. 2 is an end view of certain of the parts thereof;

Fig. 3 is a View similar to Fig. 1, showing the parts in crankingposition;

Fig. 4 is a view simllar to Fig. 1 showing the positions which the partswould assume if the teeth of the pinion should engage end to end isagainst the teeth of the engine flywheel;

Fig. 5 is a side elevation partly in section of an actuating member forthe pinion; and

Fig. 6 is an end view of the same.

Referring first to Fig. 1 of the drawing, a

An actuating member in the form of a threaded sleeve 17 is provided withsplines 18 (Figs. 5 and 6) adapted to engage the splined portion 13 ofthe shaft, and is counter-bored as indicated at 19 to allow theactuating memher to slide freely over a. considerable part of the smoothportion 11 of the driving shaft as well as the splined portion 13thereof.

Positioning means for the actuating member in the form of. a heavycompression spring 20 and a light compression spring 21 are mounted onthe smooth portion 11 of shaft 10, the heavy spring 20 being adapted tobear against a thrust ring 22 which is seated against the shoulder 12 ofshaft 10, and the light spring 21 being adapted to bear against a thrustwasher 23 which in turn bears against the end of the actuating member17. Springs 20 and 21 are both somewhat shorter than the distancebetween the thrust members 22 and 23 and spring 21 is arranged totelescope within spring 20. A connecting member in the form of a thimble24 is arranged between the telescoping portions of springs 20 and 21,and is provided with an inwardly extending flange 25 adapted to receivethe inner end of spring 21, and an outwardly extending flange 26 adaptedto form a seat for the free end of spring 20, whereby the two springsare in effect connected end to end.

Thrust member 23 extends radially beyond the spring 21 and is adapted tobear against the end flange 26 of thimble 24 after a predeterminedcompression of spring 21 so that further motion of thrust member 23 in adirection to compress the springs is resisted directly by the heavyspring without causing further compression of spring 21. The spacebetween flange 25 of thimble 24.- and the thrust ring 22 is arranged toallow for the maximum compression of spring 20.

A stop member in the form of a sleeve 27 is adapted to be mounted on theouter part of the splined portion 13 of shaft 10. Said stop member hasan out-turned shoulder 28 at one end adapted to contact and form a stopfor the end of actuating member 17, and an inturned flange 29 at itsother end adapted to bear on the smooth portion 15 of shaft 10 and seatagainst the shoulder 14 formed by the end of splined portion 13.

An anti-drift thrust member in the form of an annular Washer 30 isslidably mounted on the stop sleeve 27 and is yieldably maintainedagainst the shoulder 28 of said sleeve by means such asa lightcompression spring 31. Spring 31 is retained on the sleeve 27 by anabutment member in the form of an annulus 32 seated on the smoothportion 15 of shaft 10, bearing against the flange 29 of sleeve 27 andextending over said sleeve to form an annular recess 33 which is adaptedto house the spring 31 when the thrust washer 30 is pressed against theabutment member 32. i

The elements so far described are maintained in assembled position onshaft 10 by suitable means such as a stop nut 34 threaded on theendportion 16 of said shaft and suitably retained thereon as by means ofa cotter pin 35 engaging in castellations 36 of said nut.

A drive member which is here shown in the form of a pinion 37 is looselythreaded on the actuating member 17 and adapted to be moved thereby intoand out of engagement" with a. member of an engine to be started such asa'fiywheel gear, a portion of which is indicated at 38. Pinion 37 has ahub portion 39 extending laterally therefrom into the plane of theengine member 38 and into proximity to the anti-drift member 30 which isalso located in the plane of said engine member. Pinion 37 is thusyieldably prevented from drifting into engagement with the engine member38 while the engine is running by the anti-drift means comprising thespring 31 and thrust washer 30. Motion of said pinion away from engagingposition is limited by the heel 17 (Fig. 5) of thread 17 on actuatingmember 17, which is adapted to cooperate with a suitable conformation inthe end of pinion 37 to form a back stop for said pinion. As illustratedin Fig. 3, the meshing position of pinion 37 is determined by theabutment member 32 which limits the motion of pinion 37 into engagementwith the engine member 38.

The thread 17 on actuating member 17 may if desired be formed withapitch which is so low as to be irreversible, so that endwise pressurealone on the pinion is ineffective to move the pinion along theactuating member. This arrangement is advantageous in that it resistsany tendency for relative wheel should overrun sufiiciently to cause thepmlon 37 to overrun the actuating membcr 17, it would be the actuatingmember that would move back and forth in the bore of the pinion, whilethe latter is held in fully meshed position by virtue of the pressure ofspring 20. g

In operation, and starting with the parts as illustrated in F ig. 1,rotation of shaft 10 in a clockwise direction as viewed from the left inFig. 1 will cause the pinion 37 to be moved to the left by reason of itsinertia and its threaded engagement with the actuating member 17. Thepinion is thus caused to enter into meshing relation with the enginemember 38 until the endwise motion of the pinion is stopped by theabutment member 32.

rotated by pinion 37 and the engine cranked l) thereby. Spring 20 is sodesigned as to suitably control the. rate of deceleration of the drivingshaft 10 so as to efliciently utilize the kinetic energy stored in thearmature to as- Leo sist in initiating the rotation of the engine 1.2..

member. 7

When the engine starts, the engine member 38 is accelerated and causesthe pinion 37 to overrun the actuating member 17 whereby said actuatingmember is allowed to return to its normal position under the impulse ofsprings 20 and 21 and thereafter pinion 37 is returned to its normalposition on said actuating member as defined by the heel 17 of thethread 17', and is retained therein by means of the anti-drift spring 31and thrust member 30.

In case, during a starting operation, the teeth of the pinion 37 shouldengage end to end against the teeth of the engine member 38 thusinterrupting the motion of the driving member toward meshing position,the actuating member 17 will be moved slightly to the right as shown inFig. 4 against the resistance of the light compression spring 21. Thisspring is arranged to be sufiiciently limber so that the engagement ofthe teeth of members 37 and 38 is adequately cushioned and is thereforewithout destructive effeet. As the pressure between the actuating member17, pinion 37, and engine member 38 builds up during the compression ofspring 21, the friction between the actuating member and pinionincreases until it exceeds the friction between the pinion and enginemember. The pinion thereupon rotates slightly with the actuating memberinto registering position with the tooth-spaces of the engine member 38.Spring 21 then expands and initiates the meshing engagement of thepinion and engine member. It will be understood that the time intervalrequired to compress the spring 21 is sufiicient to allow this indexingaction of the pinion to take place. Further rotation of the drivingshaft 10 causes completion of the meshing engage ment and subsequentrotation of the engine member as above described.

It will be noted that during the cranking operation, both of the lightsprings 21 and 31 are completely housed, the former being enclosedwithin ,the thimble 24 and thrust member 23. and the latter between theabutment member 82 and the thrust washer 30,

. whereby it is impossible for centrifugal force to cause deformation ofthe springs. It will further be noted that the shoulder 28 of stopsleeve 27 is adapted to retaifnthe annular thrust Washer 30 on said,sleeve even though the actuating member 17 and pinion 37 shouldmomentarily back out of contact with said sleeve. Such a condition mightpossibly occur during handling of the motor and drive assembly, when thespring 21 might be compressed sufficiently to allow the thrust washor 30to fall back of the end of stop sleeve 27 and lock the pinion in itsretracted position. The arrangement of the shoulder 28 is alsoadvantageous in maintaining the wash er 30 on the sleeve 27 during theoperation of assembly.

Although but one form of the invention has been shown and described indetail, it will be understood that other embodiments are possible andthat changes may be made .in the construction and arrangement of theparts without departing from the spirit of the invention.

Reference will therefore be had to the actuating member toward theengine mem-' ber, and yielding means mounted on said stop for normallymaintaining the driving member out of engagement with the engine member.

2. In an engine starter drive, aemember adapted to engage and drive amember of the engine to be started, an actuating mem ber havingconnections with said driving member whereby relative rotation causesrelative translation thereof, yielding means for lightly opposinginitial longitudinal movement of the actuating member away from saidengine member, yielding means for strongly resisting further suchlongitudinal movement of the actuating member, means whereby thereaction of said light opposing means is transmitted'through saidresisting means While allowing the actuating member to act directly onthe resisting means after said initial movement thereof, a stop forlimiting longitudinal movement of the actuating member toward the enginemember, and yielding means mounted on said stop for normally maintainingthe driving member out of engagement with the engine member, said stophaving means for retaining said yielding means thereon in all operativepositions of the drive.

3. An engine starter drive including a driving shaft, an actuatingmember mounted thereon for longitudinal movement thereof and rotarymovement therewith, a stop sleeve for said actuating member mounted onsaid shaft, yielding means normally maintaining said actuating memberagainst said stop, a driving member mounted on said actuating member forlongitudinal movement thereon to engage a member of the engine to bestarted, said shaft having an abutment for said driving pinion which isrecessed immediately adjacent said sleeve, and a yielding thrust membermounted on said sleeve and interposed between said driving member andsaid abutment. V

4. An engine starter drive including a driving shaft, an actuatingmember mounted thereon for longitudinal vmovement thereof and rotarymovement therewith, a driving member mounted on said actuating memberfor rotary movement thereon and therewith and for longitudinal movementinto and out of engagement with a member of the engine to be'started, afixed stop for said actuating member in the plane of said engine member,yielding means for normally maintaining said actuating member againstsaid stop, a yielding anti-drift element for said driving member mountedon said stop in the plane of the engine member, said driving memberhaving a hub extending into proximity to said anti-drift element whensaid driving member is in its normal inoperative position.

5. An engine starter drive including a driving shaft, an actuatingmember mounted thereon for longitudinal movement thereof and rotarymovement therewith, a stop sleeve for said actuating member mounted onsaid shaft, a driving member mounted on said actuating member forlongitudinal movement thereon and rotary movement therewith to engageand drive amember of the engine to be started, said shaft having anabutment for said driving pinion which is recessed immediately adjacentsaid sleeve, and a coiled spring encircling said sleeve and interposedbetween said driving member and the abutment, with the coils at one endreceived by said annular recess, said spring extending into the plane ofthe engine member, and said driving member having a hub extending intoproximity to the end of said spring when said driving member is in itsnormal inoperative position.

'6. In an engine starter drive, a driving shaft, a hollow sleeve splinedthereon, a driving member threaded on said hollow sleeve and adapted toautomatically engage and drive a member of the engine to be started, astop for limiting movement of' the hollow sleeve toward the enginemember," yielding means opposing movement of the hollow sleeve away fromthe engine member, and yielding means on said stop normally maintainingsaid driving member out of engagement with said engine member.

7. In an engine starter drive, a driving shaft, a hollow sleeve splinedthereon, a driving member threaded on said hollow sleeve and adapted toautomatically engage and drive a member of the engine to be started, astop for limiting movement of the hollow sleeve toward the enginemember, yielding aneans opposing movement of the hollow sleeve away fromthe engine member, an annular member loosely mounted on said stopadapted to engage the driving member, yielding means urging said annularmember in a direction to maintain the driving member out of engagementwith said engine member, and an abutment for said annular memberlimiting the engaging movement of said driving member.

8. In anengine starter drive, a driving shaft, a hollow sleeve splinedthereon, a driving member threaded on said hollow sleeve and adapted toautomatically engage and drive a member of the engine to be started, a.stop for limiting movement of the hollow sleeve toward the enginemember, yielding means opposing movement of the hollow sleeve away fromthe engine member, an annular member loosely mounted on said stopadapted to engage the driving member, yielding means urging said annularmember in a direction to maintain the driving member out and adapted toautomatically engage and drive a member of the engine to be started, a

stop for limiting movement of the hollow sleeve toward the enginemember, yielding means opposing movement of the hollow sleeve away fromthe engine member, an annularanti-drift member loosely mounted on saidstop adapted to engage the driving member, yielding means urging saidannular mem ber in a direction to maintain the driving member out ofengagement with said engine member, said stop having means for retainingsaid annular member thereon, and an abutment for said annular memberlimiting the engaging movement of said driving member.

10. In an engine starter drive, a driving shaft, a threaded sleevesplined thereon, a pinion threaded on the sleeve for longitudinal motioninto and out of engagement with a member of the engine to be started, astop for limiting the engaging movement of the pinion, a light springand a heavy spring arranged to oppose longitudinal movement of thesleeve away from the engine member, the heavy spring being normallyspaced from the sleeve and adapted to engage the same after apredetermined compression of the light spring.

11. In an engine starter drive, a driving shaft, a threaded sleevesplined thereon, a pinion threaded on the sleeve for longitudinal motioninto and out of engagement with a member of the engine to be started, astop for limiting the engaging movement of the pinion, a light springand a heavy spring arranged to oppose longitudinal movement of thesleeve away from the engine member, said springs being telescoped onewithin the other, and means to place the spring functionally in serieswith each other.

12. In an engine starter drive, a driving shaft, a threaded sleevesplined thereon, a

pinion threaded on the sleeve for longitudinal motion into and out ofengagement-with a member of the engine to be started, a light spring anda heavy spring arranged to oppose longitudinal movement of the sleeveaway from the engine member, said springs being telescoped one withinthe other, and a thimble located between said springs adapted to connectthem end to end and arranged to connect the heavy spring directly Withthe sleeve after a predetermined compression of th: light spring.

In testimony whereof we have signed this specification.

WILLIAM L. MGGRATH. MAURICE P. WHITNEY.

